Merge branch 'feature_yggdrasil' into develop

Conflicts:
	gui/MainWindow.cpp
	logic/OneSixInstance.h

Fix missing session id functionality for legacy and old onesix.

24 files changed, 1846 insertions, 129 deletions

diff --git a/.gitignore b/.gitignore
index 0af63a46..597bbbec 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,3 +9,11 @@ build
 resources/CMakeFiles
 resources/MultiMCLauncher.jar
 *~
+*.swp
+
+# Ctags File
+tags
+
+# YouCompleteMe config stuff.
+.ycm_extra_conf.*
+
diff --git a/CMakeLists.txt b/CMakeLists.txt
index a9de11d1..1bb3126b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -217,6 +217,8 @@ gui/dialogs/EditNotesDialog.h
 gui/dialogs/EditNotesDialog.cpp
 gui/dialogs/CustomMessageBox.h
 gui/dialogs/CustomMessageBox.cpp
+gui/dialogs/AccountListDialog.h
+gui/dialogs/AccountListDialog.cpp
 
 # GUI - widgets
 gui/widgets/InstanceDelegate.h
@@ -269,6 +271,14 @@ logic/net/LoginTask.cpp
 logic/net/S3ListBucket.h
 logic/net/S3ListBucket.cpp
 
+# Yggdrasil login stuff
+logic/auth/MojangAccount.h
+logic/auth/MojangAccount.cpp
+logic/auth/YggdrasilTask.h
+logic/auth/YggdrasilTask.cpp
+logic/auth/AuthenticateTask.h
+logic/auth/AuthenticateTask.cpp
+
 
 # legacy instances
 logic/LegacyInstance.h
@@ -317,6 +327,8 @@ logic/lists/ForgeVersionList.h
 logic/lists/ForgeVersionList.cpp
 logic/lists/JavaVersionList.h
 logic/lists/JavaVersionList.cpp
+logic/lists/MojangAccountList.h
+logic/lists/MojangAccountList.cpp
 
 # misc model/view
 logic/EnabledItemFilter.h
@@ -359,6 +371,7 @@ gui/dialogs/IconPickerDialog.ui
 gui/dialogs/LegacyModEditDialog.ui
 gui/dialogs/OneSixModEditDialog.ui
 gui/dialogs/EditNotesDialog.ui
+gui/dialogs/AccountListDialog.ui
 
 # Widgets/other
 gui/widgets/MCModInfoFrame.ui
diff --git a/MultiMC.cpp b/MultiMC.cpp
index 0aaf31bf..17981755 100644
--- a/MultiMC.cpp
+++ b/MultiMC.cpp
@@ -10,6 +10,7 @@
 #include "gui/MainWindow.h"
 #include "gui/dialogs/VersionSelectDialog.h"
 #include "logic/lists/InstanceList.h"
+#include "logic/lists/MojangAccountList.h"
 #include "logic/lists/IconList.h"
 #include "logic/lists/LwjglVersionList.h"
 #include "logic/lists/MinecraftVersionList.h"
@@ -146,6 +147,12 @@ MultiMC::MultiMC(int &argc, char **argv) : QApplication(argc, argv)
 	connect(InstDirSetting, SIGNAL(settingChanged(const Setting &, QVariant)),
 			m_instances.get(), SLOT(on_InstFolderChanged(const Setting &, QVariant)));
 
+	// and accounts
+	m_accounts.reset(new MojangAccountList(this));
+	QLOG_INFO() << "Loading accounts...";
+	m_accounts->setListFilePath("accounts.json", true);
+	m_accounts->loadList();
+
 	// init the http meta cache
 	initHttpMetaCache();
 
diff --git a/MultiMC.h b/MultiMC.h
index cd4a5f7d..dba923b1 100644
--- a/MultiMC.h
+++ b/MultiMC.h
@@ -13,6 +13,7 @@ class LWJGLVersionList;
 class HttpMetaCache;
 class SettingsObject;
 class InstanceList;
+class MojangAccountList;
 class IconList;
 class QNetworkAccessManager;
 class ForgeVersionList;
@@ -57,6 +58,11 @@ public:
 		return m_instances;
 	}
 
+	std::shared_ptr<MojangAccountList> accounts()
+	{
+		return m_accounts;
+	}
+
 	std::shared_ptr<IconList> icons();
 
 	Status status()
@@ -101,6 +107,7 @@ private:
 	std::shared_ptr<QTranslator> m_mmc_translator;
 	std::shared_ptr<SettingsObject> m_settings;
 	std::shared_ptr<InstanceList> m_instances;
+	std::shared_ptr<MojangAccountList> m_accounts;
 	std::shared_ptr<IconList> m_icons;
 	std::shared_ptr<QNetworkAccessManager> m_qnam;
 	std::shared_ptr<HttpMetaCache> m_metacache;
diff --git a/gui/MainWindow.cpp b/gui/MainWindow.cpp
index b8766d9a..6ae41f50 100644
--- a/gui/MainWindow.cpp
+++ b/gui/MainWindow.cpp
@@ -57,6 +57,7 @@
 #include "gui/dialogs/IconPickerDialog.h"
 #include "gui/dialogs/EditNotesDialog.h"
 #include "gui/dialogs/CopyInstanceDialog.h"
+#include "gui/dialogs/AccountListDialog.h"
 
 #include "gui/ConsoleWindow.h"
 
@@ -84,11 +85,6 @@ MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWi
 	ui->setupUi(this);
 	setWindowTitle(QString("MultiMC %1").arg(MMC->version().toString()));
 
-	// Set the selected instance to null
-	m_selectedInstance = nullptr;
-	// Set active instance to null.
-	m_activeInst = nullptr;
-
 	// OSX magic.
 	setUnifiedTitleAndToolBarOnMac(true);
 
@@ -428,6 +424,12 @@ void MainWindow::on_actionSettings_triggered()
 	proxymodel->sort(0);
 }
 
+void MainWindow::on_actionManageAccounts_triggered()
+{
+	AccountListDialog dialog(this);
+	dialog.exec();
+}
+
 void MainWindow::on_actionReportBug_triggered()
 {
 	openWebPage(QUrl("http://multimc.myjetbrains.com/youtrack/dashboard#newissue=yes"));
@@ -538,11 +540,7 @@ void MainWindow::instanceActivated(QModelIndex index)
 
 	NagUtils::checkJVMArgs(inst->settings().get("JvmArgs").toString(), this);
 
-	bool autoLogin = inst->settings().get("AutoLogin").toBool();
-	if (autoLogin)
-		doAutoLogin();
-	else
-		doLogin();
+	doLogin();
 }
 
 void MainWindow::on_actionLaunchInstance_triggered()
@@ -554,106 +552,74 @@ void MainWindow::on_actionLaunchInstance_triggered()
 	}
 }
 
-void MainWindow::doAutoLogin()
+void MainWindow::doLogin(const QString &errorMsg)
 {
 	if (!m_selectedInstance)
 		return;
 
-	Keyring *k = Keyring::instance();
-	QStringList accounts = k->getStoredAccounts("minecraft");
-
-	if (!accounts.isEmpty())
+	// Find an account to use.
+	std::shared_ptr<MojangAccountList> accounts = MMC->accounts();
+	MojangAccountPtr account = accounts->activeAccount();
+	if (accounts->count() <= 0)
 	{
-		QString username = accounts[0];
-		QString password = k->getPassword("minecraft", username);
+		// Tell the user they need to log in at least one account in order to play.
+		auto reply = CustomMessageBox::selectable(this, tr("No Accounts"),
+			tr("In order to play Minecraft, you must have at least one Mojang or Minecraft account logged in to MultiMC."
+				"Would you like to open the account manager to add an account now?"),
+			QMessageBox::Information, QMessageBox::Yes | QMessageBox::No)->exec();
 
-		if (!password.isEmpty())
-		{
-			QLOG_INFO() << "Automatically logging in with stored account: " << username;
-			m_activeInst = m_selectedInstance;
-			doLogin(username, password);
-		}
-		else
+		if (reply == QMessageBox::Yes)
 		{
-			QLOG_ERROR() << "Auto login set for account, but no password was found: "
-						 << username;
-			doLogin(tr("Auto login attempted, but no password is stored."));
+			// Open the account manager.
+			on_actionManageAccounts_triggered();
 		}
 	}
-	else
+	else if (account.get() == nullptr)
 	{
-		QLOG_ERROR() << "Auto login set but no accounts were stored.";
-		doLogin(tr("Auto login attempted, but no accounts are stored."));
-	}
-}
-
-void MainWindow::doLogin(QString username, QString password)
-{
-	PasswordLogin uInfo{username, password};
-
-	ProgressDialog *tDialog = new ProgressDialog(this);
-	LoginTask *loginTask = new LoginTask(uInfo, tDialog);
-	connect(loginTask, SIGNAL(succeeded()), SLOT(onLoginComplete()), Qt::QueuedConnection);
-	connect(loginTask, SIGNAL(failed(QString)), SLOT(doLogin(QString)), Qt::QueuedConnection);
-
-	tDialog->exec(loginTask);
-}
-
-void MainWindow::doLogin(const QString &errorMsg)
-{
-	if (!m_selectedInstance)
-		return;
+		// Tell the user they need to log in at least one account in order to play.
+		auto reply = CustomMessageBox::selectable(this, tr("No Account Selected"),
+			tr("You don't have an account selected as an active account."
+				"Would you like to open the account manager to select one now?"),
+			QMessageBox::Information, QMessageBox::Yes | QMessageBox::No)->exec();
 
-	LoginDialog *loginDlg = new LoginDialog(this, errorMsg);
-	if (!m_selectedInstance->lastLaunch())
-		loginDlg->forceOnline();
-
-	loginDlg->exec();
-	if (loginDlg->result() == QDialog::Accepted)
-	{
-		if (loginDlg->isOnline())
+		if (reply == QMessageBox::Yes)
 		{
-			m_activeInst = m_selectedInstance;
-			doLogin(loginDlg->getUsername(), loginDlg->getPassword());
-		}
-		else
-		{
-			QString user = loginDlg->getUsername();
-			if (user.length() == 0)
-				user = QString("Player");
-			m_activeLogin = {user, QString("Offline"), user, QString()};
-			m_activeInst = m_selectedInstance;
-			launchInstance(m_activeInst, m_activeLogin);
+			// Open the account manager.
+			on_actionManageAccounts_triggered();
 		}
 	}
+	else
+	{
+		// We'll need to validate the access token to make sure the account is still logged in.
+		// TODO: Do that ^
+		
+		prepareLaunch(m_selectedInstance, account);
+	}
 }
 
-void MainWindow::onLoginComplete()
+void MainWindow::prepareLaunch(BaseInstance* instance, MojangAccountPtr account)
 {
-	if (!m_activeInst)
-		return;
-	LoginTask *task = (LoginTask *)QObject::sender();
-	m_activeLogin = task->getResult();
-
-	Task *updateTask = m_activeInst->doUpdate();
+	Task *updateTask = instance->doUpdate();
 	if (!updateTask)
 	{
-		launchInstance(m_activeInst, m_activeLogin);
+		launchInstance(instance, account);
 	}
 	else
 	{
 		ProgressDialog tDialog(this);
-		connect(updateTask, SIGNAL(succeeded()), SLOT(onGameUpdateComplete()));
+		connect(updateTask, &Task::succeeded, [this, instance, account] { launchInstance(instance, account); });
 		connect(updateTask, SIGNAL(failed(QString)), SLOT(onGameUpdateError(QString)));
 		tDialog.exec(updateTask);
 		delete updateTask;
 	}
 
-	auto job = new NetJob("Player skin: " + m_activeLogin.player_name);
+	QString playerName = account->currentProfile()->name();
 
-	auto meta = MMC->metacache()->resolveEntry("skins", m_activeLogin.player_name + ".png");
+	auto job = new NetJob("Player skin: " + playerName);
+
+	auto meta = MMC->metacache()->resolveEntry("skins", playerName + ".png");
 	auto action = CacheDownload::make(
-		QUrl("http://skins.minecraft.net/MinecraftSkins/" + m_activeLogin.player_name + ".png"),
+		QUrl("http://skins.minecraft.net/MinecraftSkins/" + playerName + ".png"),
 		meta);
 	job->addNetAction(action);
 	meta->stale = true;
@@ -678,12 +644,12 @@ void MainWindow::onLoginComplete()
 	QJsonDocument jsonDoc = QJsonDocument::fromJson(data, &jsonError);
 	QJsonObject root = jsonDoc.object();
 	QJsonObject mappings = root.value("mappings").toObject();
-	QJsonArray usernames = mappings.value(m_activeLogin.username).toArray();
+	QJsonArray usernames = mappings.value(account->username()).toArray();
 
-	if (!usernames.contains(m_activeLogin.player_name))
+	if (!usernames.contains(playerName))
 	{
-		usernames.prepend(m_activeLogin.player_name);
-		mappings[m_activeLogin.username] = usernames;
+		usernames.prepend(playerName);
+		mappings[account->username()] = usernames;
 		root["mappings"] = mappings;
 		jsonDoc.setObject(root);
 
@@ -693,22 +659,12 @@ void MainWindow::onLoginComplete()
 	}
 }
 
-void MainWindow::onGameUpdateComplete()
-{
-	launchInstance(m_activeInst, m_activeLogin);
-}
-
-void MainWindow::onGameUpdateError(QString error)
-{
-	CustomMessageBox::selectable(this, tr("Error updating instance"), error,
-								 QMessageBox::Warning)->show();
-}
-
-void MainWindow::launchInstance(BaseInstance *instance, LoginResponse response)
+void MainWindow::launchInstance(BaseInstance *instance, MojangAccountPtr account)
 {
 	Q_ASSERT_X(instance != NULL, "launchInstance", "instance is NULL");
+	Q_ASSERT_X(account.get() != nullptr, "launchInstance", "account is NULL");
 
-	proc = instance->prepareForLaunch(response);
+	proc = instance->prepareForLaunch(account);
 	if (!proc)
 		return;
 
@@ -717,10 +673,19 @@ void MainWindow::launchInstance(BaseInstance *instance, LoginResponse response)
 	console = new ConsoleWindow(proc);
 	connect(console, SIGNAL(isClosing()), this, SLOT(instanceEnded()));
 
-	proc->setLogin(response.username, response.session_id);
+	// I think this will work...
+	QString username = account->username();
+	QString session_id = account->accessToken();
+	proc->setLogin(username, session_id);
 	proc->launch();
 }
 
+void MainWindow::onGameUpdateError(QString error)
+{
+	CustomMessageBox::selectable(this, tr("Error updating instance"), error,
+								 QMessageBox::Warning)->show();
+}
+
 void MainWindow::taskStart()
 {
 	// Nothing to do here yet.
diff --git a/gui/MainWindow.h b/gui/MainWindow.h
index b1678f76..3b8d4668 100644
--- a/gui/MainWindow.h
+++ b/gui/MainWindow.h
@@ -22,6 +22,8 @@
 #include "logic/net/LoginTask.h"
 #include "logic/BaseInstance.h"
 
+#include "logic/auth/MojangAccount.h"
+
 class QToolButton;
 class LabeledToolButton;
 class QLabel;
@@ -80,6 +82,8 @@ slots:
 
 	void on_actionSettings_triggered();
 
+	void on_actionManageAccounts_triggered();
+
 	void on_actionReportBug_triggered();
 
 	void on_actionNews_triggered();
@@ -103,12 +107,18 @@ slots:
 	void on_actionEditInstNotes_triggered();
 
 	void doLogin(const QString &errorMsg = "");
-	void doLogin(QString username, QString password);
-	void doAutoLogin();
 
-	void onLoginComplete();
+	/*!
+	 * Launches the given instance with the given account.
+	 * This function assumes that the given account has a valid, usable access token.
+	 */
+	void launchInstance(BaseInstance* instance, MojangAccountPtr account);
+
+	/*!
+	 * Prepares the given instance for launch with the given account.
+	 */
+	void prepareLaunch(BaseInstance* instance, MojangAccountPtr account);
 
-	void onGameUpdateComplete();
 	void onGameUpdateError(QString error);
 
 	void taskStart();
@@ -136,8 +146,6 @@ slots:
 
 	void startTask(Task *task);
 
-	void launchInstance(BaseInstance *inst, LoginResponse response);
-
 protected:
 	bool eventFilter(QObject *obj, QEvent *ev);
 	void setCatBackground(bool enabled);
@@ -155,12 +163,6 @@ private:
 
 	BaseInstance *m_selectedInstance;
 
-	// A pointer to the instance we are actively doing stuff with.
-	// This is set when the user launches an instance and is used to refer to that
-	// instance throughout the launching process.
-	BaseInstance *m_activeInst;
-	LoginResponse m_activeLogin;
-
 	Task *m_versionLoadTask;
 
 	QLabel *m_statusLeft;
diff --git a/gui/MainWindow.ui b/gui/MainWindow.ui
index 6f70fc98..f76d4d4e 100644
--- a/gui/MainWindow.ui
+++ b/gui/MainWindow.ui
@@ -70,6 +70,7 @@
    <addaction name="separator"/>
    <addaction name="actionCheckUpdate"/>
    <addaction name="actionSettings"/>
+   <addaction name="actionManageAccounts"/>
    <addaction name="separator"/>
    <addaction name="actionReportBug"/>
    <addaction name="actionNews"/>
@@ -465,6 +466,14 @@
     <string>Add a new instance.</string>
    </property>
   </action>
+  <action name="actionManageAccounts">
+   <property name="text">
+    <string>Manage Accounts</string>
+   </property>
+   <property name="toolTip">
+    <string>Manage your Mojang or Minecraft accounts.</string>
+   </property>
+  </action>
  </widget>
  <layoutdefault spacing="6" margin="11"/>
  <resources>
diff --git a/gui/dialogs/AccountListDialog.cpp b/gui/dialogs/AccountListDialog.cpp
new file mode 100644
index 00000000..c685c164
--- /dev/null
+++ b/gui/dialogs/AccountListDialog.cpp
@@ -0,0 +1,112 @@
+/* Copyright 2013 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "AccountListDialog.h"
+#include "ui_AccountListDialog.h"
+
+#include <QItemSelectionModel>
+
+#include <logger/QsLog.h>
+
+#include <logic/auth/AuthenticateTask.h>
+
+#include <gui/dialogs/LoginDialog.h>
+#include <gui/dialogs/ProgressDialog.h>
+
+#include <MultiMC.h>
+
+AccountListDialog::AccountListDialog(QWidget *parent) :
+	QDialog(parent),
+	ui(new Ui::AccountListDialog)
+{
+	ui->setupUi(this);
+
+	m_accounts = MMC->accounts();
+	// TODO: Make the "Active?" column show checkboxes or radio buttons.
+	ui->listView->setModel(m_accounts.get());
+}
+
+AccountListDialog::~AccountListDialog()
+{
+	delete ui;
+}
+
+
+void AccountListDialog::on_addAccountBtn_clicked()
+{
+	doLogin("Please log in to add your account.");
+}
+
+void AccountListDialog::on_rmAccountBtn_clicked()
+{
+	QModelIndexList selection = ui->listView->selectionModel()->selectedIndexes();
+	if (selection.size() > 0)
+	{
+		QModelIndex selected = selection.first();
+		m_accounts->removeAccount(selected);
+	}
+}
+
+void AccountListDialog::on_editAccountBtn_clicked()
+{
+	// TODO
+}
+
+void AccountListDialog::on_setActiveBtn_clicked()
+{
+	QModelIndexList selection = ui->listView->selectionModel()->selectedIndexes();
+	if (selection.size() > 0)
+	{
+		QModelIndex selected = selection.first();
+		MojangAccountPtr account = selected.data(MojangAccountList::PointerRole).value<MojangAccountPtr>();
+		m_accounts->setActiveAccount(account->username());
+	}
+}
+
+void AccountListDialog::on_closeBtnBox_rejected()
+{
+	close();
+}
+
+void AccountListDialog::doLogin(const QString& errMsg)
+{
+	// TODO: We can use the login dialog for this for now, but we'll have to make something better for it eventually.
+	LoginDialog loginDialog(this);
+	loginDialog.exec();
+
+	if (loginDialog.result() == QDialog::Accepted)
+	{
+		QString username(loginDialog.getUsername());
+		QString password(loginDialog.getPassword());
+
+		MojangAccountPtr account = MojangAccountPtr(new MojangAccount(username));
+
+		ProgressDialog* progDialog = new ProgressDialog(this);
+		m_authTask = new AuthenticateTask(account, password, progDialog);
+		connect(m_authTask, SIGNAL(succeeded()), SLOT(onLoginComplete()), Qt::QueuedConnection);
+		connect(m_authTask, SIGNAL(failed(QString)), SLOT(doLogin(QString)), Qt::QueuedConnection);
+		progDialog->exec(m_authTask);
+		//delete m_authTask;
+	}
+}
+
+void AccountListDialog::onLoginComplete()
+{
+	// Add the authenticated account to the accounts list.
+	MojangAccountPtr account = m_authTask->getMojangAccount();
+	m_accounts->addAccount(account);
+	//ui->listView->update();
+}
+
diff --git a/gui/dialogs/AccountListDialog.h b/gui/dialogs/AccountListDialog.h
new file mode 100644
index 00000000..17a50bec
--- /dev/null
+++ b/gui/dialogs/AccountListDialog.h
@@ -0,0 +1,63 @@
+/* Copyright 2013 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <QDialog>
+
+#include <memory>
+
+#include "logic/lists/MojangAccountList.h"
+
+namespace Ui {
+class AccountListDialog;
+}
+
+class AuthenticateTask;
+
+class AccountListDialog : public QDialog
+{
+Q_OBJECT
+public:
+	explicit AccountListDialog(QWidget *parent = 0);
+	~AccountListDialog();
+
+public
+slots:
+	void on_addAccountBtn_clicked();
+
+	void on_rmAccountBtn_clicked();
+
+	void on_editAccountBtn_clicked();
+
+	void on_setActiveBtn_clicked();
+
+	// This will be sent when the "close" button is clicked.
+	void on_closeBtnBox_rejected();
+
+protected:
+	std::shared_ptr<MojangAccountList> m_accounts;
+
+	AuthenticateTask* m_authTask;
+
+protected
+slots:
+	void doLogin(const QString& errMsg="");
+	void onLoginComplete();
+
+private:
+	Ui::AccountListDialog *ui;
+};
+
diff --git a/gui/dialogs/AccountListDialog.ui b/gui/dialogs/AccountListDialog.ui
new file mode 100644
index 00000000..2872b368
--- /dev/null
+++ b/gui/dialogs/AccountListDialog.ui
@@ -0,0 +1,93 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>AccountListDialog</class>
+ <widget class="QDialog" name="AccountListDialog">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>400</width>
+    <height>300</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Dialog</string>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout_2">
+   <item>
+    <widget class="QLabel" name="welcomeLabel">
+     <property name="text">
+      <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Welcome! If you're new here, you can click the &amp;quot;Add&amp;quot; button to add your Mojang or Minecraft account.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+     </property>
+     <property name="wordWrap">
+      <bool>true</bool>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <layout class="QHBoxLayout" name="horizontalLayout">
+     <item>
+      <widget class="QTreeView" name="listView"/>
+     </item>
+     <item>
+      <layout class="QVBoxLayout" name="manageAcctsBtnBox">
+       <item>
+        <widget class="QPushButton" name="addAccountBtn">
+         <property name="text">
+          <string>&amp;Add</string>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QPushButton" name="editAccountBtn">
+         <property name="text">
+          <string>&amp;Edit</string>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <widget class="QPushButton" name="rmAccountBtn">
+         <property name="text">
+          <string>&amp;Remove</string>
+         </property>
+        </widget>
+       </item>
+       <item>
+        <spacer name="buttonSpacer">
+         <property name="orientation">
+          <enum>Qt::Vertical</enum>
+         </property>
+         <property name="sizeHint" stdset="0">
+          <size>
+           <width>20</width>
+           <height>40</height>
+          </size>
+         </property>
+        </spacer>
+       </item>
+       <item>
+        <widget class="QPushButton" name="setActiveBtn">
+         <property name="toolTip">
+          <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Set the currently selected account as the active account. The active account is the account that is used to log in (unless it is overridden in an instance-specific setting).&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+         </property>
+         <property name="text">
+          <string>&amp;Set Active</string>
+         </property>
+        </widget>
+       </item>
+      </layout>
+     </item>
+    </layout>
+   </item>
+   <item>
+    <widget class="QDialogButtonBox" name="closeBtnBox">
+     <property name="standardButtons">
+      <set>QDialogButtonBox::Close</set>
+     </property>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>
diff --git a/logic/BaseInstance.h b/logic/BaseInstance.h
index 6c9b16c7..cf86fda6 100644
--- a/logic/BaseInstance.h
+++ b/logic/BaseInstance.h
@@ -22,7 +22,7 @@
 
 #include "inifile.h"
 #include "lists/BaseVersionList.h"
-#include "net/LoginTask.h"
+#include "logic/auth/MojangAccount.h"
 
 class QDialog;
 class Task;
@@ -153,8 +153,8 @@ public:
 	/// returns a valid update task if update is needed, NULL otherwise
 	virtual Task *doUpdate() = 0;
 
-	/// returns a valid minecraft process, ready for launch
-	virtual MinecraftProcess *prepareForLaunch(LoginResponse response) = 0;
+	/// returns a valid minecraft process, ready for launch with the given account.
+	virtual MinecraftProcess *prepareForLaunch(MojangAccountPtr account) = 0;
 
 	/// do any necessary cleanups after the instance finishes. also runs before
 	/// 'prepareForLaunch'
diff --git a/logic/InstanceLauncher.cpp b/logic/InstanceLauncher.cpp
index 534d07d1..0ef0f045 100644
--- a/logic/InstanceLauncher.cpp
+++ b/logic/InstanceLauncher.cpp
@@ -38,6 +38,8 @@ void InstanceLauncher::onTerminated()
 
 void InstanceLauncher::onLoginComplete()
 {
+	// TODO: Fix this.
+	/*
 	LoginTask *task = (LoginTask *)QObject::sender();
 	auto result = task->getResult();
 	auto instance = MMC->instances()->getInstanceById(instId);
@@ -52,6 +54,7 @@ void InstanceLauncher::onLoginComplete()
 
 	proc->setLogin(result.username, result.session_id);
 	proc->launch();
+	*/
 }
 
 void InstanceLauncher::doLogin(const QString &errorMsg)
diff --git a/logic/LegacyInstance.cpp b/logic/LegacyInstance.cpp
index 07e302f5..ab6536d0 100644
--- a/logic/LegacyInstance.cpp
+++ b/logic/LegacyInstance.cpp
@@ -50,7 +50,7 @@ Task *LegacyInstance::doUpdate()
 	return new LegacyUpdate(this, this);
 }
 
-MinecraftProcess *LegacyInstance::prepareForLaunch(LoginResponse response)
+MinecraftProcess *LegacyInstance::prepareForLaunch(MojangAccountPtr account)
 {
 	MinecraftProcess *proc = new MinecraftProcess(this);
 
@@ -103,8 +103,8 @@ MinecraftProcess *LegacyInstance::prepareForLaunch(LoginResponse response)
 #endif
 
 		args << "-jar" << LAUNCHER_FILE;
-		args << response.player_name;
-		args << response.session_id;
+		args << account->currentProfile()->name();
+		args << account->sessionId();
 		args << windowTitle;
 		args << windowSize;
 		args << lwjgl;
diff --git a/logic/LegacyInstance.h b/logic/LegacyInstance.h
index 04b16b9b..3d35521e 100644
--- a/logic/LegacyInstance.h
+++ b/logic/LegacyInstance.h
@@ -80,7 +80,7 @@ public:
 	virtual void setShouldUpdate(bool val);
 	virtual Task *doUpdate();
 
-	virtual MinecraftProcess *prepareForLaunch(LoginResponse response);
+	virtual MinecraftProcess *prepareForLaunch(MojangAccountPtr account);
 	virtual void cleanupAfterRun();
 	virtual QDialog *createModEditDialog(QWidget *parent);
 
@@ -93,4 +93,4 @@ public:
 protected
 slots:
 	virtual void jarModsChanged();
-};
\ No newline at end of file
+};
diff --git a/logic/OneSixInstance.cpp b/logic/OneSixInstance.cpp
index 7764d225..a947b7c0 100644
--- a/logic/OneSixInstance.cpp
+++ b/logic/OneSixInstance.cpp
@@ -66,7 +66,7 @@ QString replaceTokensIn(QString text, QMap<QString, QString> with)
 	return result;
 }
 
-QStringList OneSixInstance::processMinecraftArgs(LoginResponse response)
+QStringList OneSixInstance::processMinecraftArgs(MojangAccountPtr account)
 {
 	I_D(OneSixInstance);
 	auto version = d->version;
@@ -74,11 +74,11 @@ QStringList OneSixInstance::processMinecraftArgs(LoginResponse response)
 
 	QMap<QString, QString> token_mapping;
 	// yggdrasil!
-	token_mapping["auth_username"] = response.username;
-	token_mapping["auth_session"] = response.session_id;
-	token_mapping["auth_access_token"] = response.access_token;
-	token_mapping["auth_player_name"] = response.player_name;
-	token_mapping["auth_uuid"] = response.player_id;
+	token_mapping["auth_username"] = account->username();
+	token_mapping["auth_session"] = account->sessionId();
+	token_mapping["auth_access_token"] = account->accessToken();
+	token_mapping["auth_player_name"] = account->currentProfile()->name();
+	token_mapping["auth_uuid"] = account->currentProfile()->id();
 
 	// this is for offline?:
 	/*
@@ -105,7 +105,7 @@ QStringList OneSixInstance::processMinecraftArgs(LoginResponse response)
 	return parts;
 }
 
-MinecraftProcess *OneSixInstance::prepareForLaunch(LoginResponse response)
+MinecraftProcess *OneSixInstance::prepareForLaunch(MojangAccountPtr account)
 {
 	I_D(OneSixInstance);
 	cleanupAfterRun();
@@ -177,7 +177,7 @@ MinecraftProcess *OneSixInstance::prepareForLaunch(LoginResponse response)
 		args << classPath;
 	}
 	args << version->mainClass;
-	args.append(processMinecraftArgs(response));
+	args.append(processMinecraftArgs(account));
 
 	// Set the width and height for 1.6 instances
 	bool maximize = settings().get("LaunchMaximized").toBool();
diff --git a/logic/OneSixInstance.h b/logic/OneSixInstance.h
index 2d44ddba..e30ca7ca 100644
--- a/logic/OneSixInstance.h
+++ b/logic/OneSixInstance.h
@@ -40,7 +40,8 @@ public:
 	virtual QString instanceConfigFolder() const;
 
 	virtual Task *doUpdate();
-	virtual MinecraftProcess *prepareForLaunch(LoginResponse response);
+	virtual MinecraftProcess *prepareForLaunch(MojangAccountPtr account);
+
 	virtual void cleanupAfterRun();
 
 	virtual QString intendedVersionId() const;
@@ -72,5 +73,5 @@ public:
 	virtual QString getStatusbarDescription();
 
 private:
-	QStringList processMinecraftArgs(LoginResponse response);
-};
\ No newline at end of file
+	QStringList processMinecraftArgs(MojangAccountPtr account);
+};
diff --git a/logic/auth/AuthenticateTask.cpp b/logic/auth/AuthenticateTask.cpp
new file mode 100644
index 00000000..a9c2c03f
--- /dev/null
+++ b/logic/auth/AuthenticateTask.cpp
@@ -0,0 +1,180 @@
+
+/* Copyright 2013 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <logic/auth/AuthenticateTask.h>
+
+#include <logic/auth/MojangAccount.h>
+
+#include <QJsonDocument>
+#include <QJsonObject>
+#include <QJsonArray>
+#include <QVariant>
+#include <QDebug>
+
+#include "logger/QsLog.h"
+
+AuthenticateTask::AuthenticateTask(MojangAccountPtr account, const QString& password, QObject* parent) :
+	YggdrasilTask(account, parent), m_password(password)
+{
+}
+
+QJsonObject AuthenticateTask::getRequestContent() const
+{
+	/*
+	 * {
+	 *   "agent": {								// optional
+	 *   "name": "Minecraft",					// So far this is the only encountered value
+ 	 *   "version": 1							// This number might be increased
+	 * 											// by the vanilla client in the future
+	 *   },
+	 *   "username": "mojang account name",		// Can be an email address or player name for
+												// unmigrated accounts
+	 *  "password": "mojang account password",
+	 *  "clientToken": "client identifier"		// optional
+	 * }
+	 */
+	QJsonObject req;
+
+	{
+		QJsonObject agent;
+		// C++ makes string literals void* for some stupid reason, so we have to tell it QString... Thanks Obama.
+		agent.insert("name", QString("Minecraft"));
+		agent.insert("version", 1);
+		req.insert("agent", agent);
+	}
+
+	req.insert("username", getMojangAccount()->username());
+	req.insert("password", m_password);
+
+	// If we already have a client token, give it to the server.
+	// Otherwise, let the server give us one.
+	if (!getMojangAccount()->clientToken().isEmpty())
+		req.insert("clientToken", getMojangAccount()->clientToken());
+
+	return req;
+}
+
+bool AuthenticateTask::processResponse(QJsonObject responseData)
+{
+	// Read the response data. We need to get the client token, access token, and the selected profile.
+	QLOG_DEBUG() << "Processing authentication response.";
+	
+	// If we already have a client token, make sure the one the server gave us matches our existing one.
+	QLOG_DEBUG() << "Getting client token.";
+	QString clientToken = responseData.value("clientToken").toString("");
+	if (clientToken.isEmpty())
+	{
+		// Fail if the server gave us an empty client token
+		// TODO: Set an error properly to display to the user.
+		QLOG_ERROR() << "Server didn't send a client token.";
+		return false;
+	}
+	if (!getMojangAccount()->clientToken().isEmpty() && clientToken != getMojangAccount()->clientToken())
+	{
+		// The server changed our client token! Obey its wishes, but complain. That's what I do for my parents, so...
+		QLOG_WARN() << "Server changed our client token to '" << clientToken 
+					<< "'. This shouldn't happen, but it isn't really a big deal.";
+	}
+	// Set the client token.
+	getMojangAccount()->setClientToken(clientToken);
+
+
+	// Now, we set the access token.
+	QLOG_DEBUG() << "Getting access token.";
+	QString accessToken = responseData.value("accessToken").toString("");
+	if (accessToken.isEmpty())
+	{
+		// Fail if the server didn't give us an access token.
+		// TODO: Set an error properly to display to the user.
+		QLOG_ERROR() << "Server didn't send an access token.";
+	}
+	// Set the access token.
+	getMojangAccount()->setAccessToken(accessToken);
+
+
+	// Now we load the list of available profiles.
+	// Mojang hasn't yet implemented the profile system, 
+	// but we might as well support what's there so we 
+	// don't have trouble implementing it later.
+	QLOG_DEBUG() << "Loading profile list.";
+	QJsonArray availableProfiles = responseData.value("availableProfiles").toArray();
+	ProfileList loadedProfiles;
+	for (auto iter : availableProfiles)
+	{
+		QJsonObject profile = iter.toObject();
+		// Profiles are easy, we just need their ID and name.
+		QString id = profile.value("id").toString("");
+		QString name = profile.value("name").toString("");
+
+		if (id.isEmpty() || name.isEmpty())
+		{
+			// This should never happen, but we might as well 
+			// warn about it if it does so we can debug it easily.
+			// You never know when Mojang might do something truly derpy.
+			QLOG_WARN() << "Found entry in available profiles list with missing ID or name field. Ignoring it.";
+		}
+
+		// Now, add a new AccountProfile entry to the list.
+		loadedProfiles.append(AccountProfile(id, name));
+	}
+	// Put the list of profiles we loaded into the MojangAccount object.
+	getMojangAccount()->loadProfiles(loadedProfiles);
+
+
+	// Finally, we set the current profile to the correct value. This is pretty simple.
+	// We do need to make sure that the current profile that the server gave us 
+	// is actually in the available profiles list.
+	// If it isn't, we'll just fail horribly (*shouldn't* ever happen, but you never know).
+	QLOG_DEBUG() << "Setting current profile.";
+	QJsonObject currentProfile = responseData.value("selectedProfile").toObject();
+	QString currentProfileId = currentProfile.value("id").toString("");
+	if (currentProfileId.isEmpty())
+	{
+		// TODO: Set an error to display to the user.
+		QLOG_ERROR() << "Server didn't specify a currently selected profile.";
+		return false;
+	}
+	if (!getMojangAccount()->setProfile(currentProfileId))
+	{
+		// TODO: Set an error to display to the user.
+		QLOG_ERROR() << "Server specified a selected profile that wasn't in the available profiles list.";
+		return false;
+	}
+	
+	
+	// We've made it through the minefield of possible errors. Return true to indicate that we've succeeded.
+	QLOG_DEBUG() << "Finished reading authentication response.";
+	return true;
+}
+
+QString AuthenticateTask::getEndpoint() const
+{
+	return "authenticate";
+}
+
+QString AuthenticateTask::getStateMessage(const YggdrasilTask::State state) const
+{
+	switch (state)
+	{
+	case STATE_SENDING_REQUEST:
+		return tr("Authenticating: Sending request.");
+	case STATE_PROCESSING_RESPONSE:
+		return tr("Authenticating: Processing response.");
+	default:
+		return YggdrasilTask::getStateMessage(state);
+	}
+}
+
diff --git a/logic/auth/AuthenticateTask.h b/logic/auth/AuthenticateTask.h
new file mode 100644
index 00000000..54a6b79a
--- /dev/null
+++ b/logic/auth/AuthenticateTask.h
@@ -0,0 +1,46 @@
+/* Copyright 2013 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <logic/auth/YggdrasilTask.h>
+
+#include <QObject>
+#include <QString>
+#include <QJsonObject>
+
+/**
+ * The authenticate task takes a MojangAccount with no access token and password and attempts to authenticate with Mojang's servers.
+ * If successful, it will set the MojangAccount's access token.
+ */
+class AuthenticateTask : public YggdrasilTask
+{
+Q_OBJECT
+public:
+	AuthenticateTask(MojangAccountPtr account, const QString& password, QObject* parent=0);
+
+protected:
+	virtual QJsonObject getRequestContent() const;
+	
+	virtual QString getEndpoint() const;
+
+	virtual bool processResponse(QJsonObject responseData);
+	
+	QString getStateMessage(const YggdrasilTask::State state) const;
+
+private:
+	QString m_password;
+};
+
diff --git a/logic/auth/MojangAccount.cpp b/logic/auth/MojangAccount.cpp
new file mode 100644
index 00000000..4f3839bc
--- /dev/null
+++ b/logic/auth/MojangAccount.cpp
@@ -0,0 +1,220 @@
+/* Copyright 2013 MultiMC Contributors
+ *
+ * Authors: Orochimarufan <orochimarufan.x3@gmail.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "MojangAccount.h"
+
+#include <QUuid>
+#include <QJsonObject>
+#include <QJsonArray>
+
+#include <logger/QsLog.h>
+
+MojangAccount::MojangAccount(const QString& username, QObject* parent) :
+	QObject(parent)
+{
+	// Generate a client token.
+	m_clientToken = QUuid::createUuid().toString();
+
+	m_username = username;
+
+	m_currentProfile = -1;
+}
+
+MojangAccount::MojangAccount(const QString& username, const QString& clientToken, 
+							 const QString& accessToken, QObject* parent) :
+	QObject(parent)
+{
+	m_username = username;
+	m_clientToken = clientToken;
+	m_accessToken = accessToken;
+
+	m_currentProfile = -1;
+}
+
+MojangAccount::MojangAccount(const MojangAccount& other, QObject* parent)
+{
+	m_username = other.username();
+	m_clientToken = other.clientToken();
+	m_accessToken = other.accessToken();
+
+	m_profiles = other.m_profiles;
+	m_currentProfile = other.m_currentProfile;
+}
+
+
+QString MojangAccount::username() const
+{
+	return m_username;
+}
+
+QString MojangAccount::clientToken() const
+{
+	return m_clientToken;
+}
+
+void MojangAccount::setClientToken(const QString& clientToken)
+{
+	m_clientToken = clientToken;
+}
+
+
+QString MojangAccount::accessToken() const
+{
+	return m_accessToken;
+}
+
+void MojangAccount::setAccessToken(const QString& accessToken)
+{
+	m_accessToken = accessToken;
+}
+
+QString MojangAccount::sessionId() const
+{
+	return "token:" + m_accessToken + ":" + currentProfile()->id();
+}
+
+const QList<AccountProfile> MojangAccount::profiles() const
+{
+	return m_profiles;
+}
+
+const AccountProfile* MojangAccount::currentProfile() const
+{
+	if (m_currentProfile < 0)
+	{
+		if (m_profiles.length() > 0)
+			return &m_profiles.at(0);
+		else
+			return nullptr;
+	}
+	else
+		return &m_profiles.at(m_currentProfile);
+}
+
+bool MojangAccount::setProfile(const QString& profileId)
+{
+	const QList<AccountProfile>& profiles = this->profiles();
+	for (int i = 0; i < profiles.length(); i++)
+	{
+		if (profiles.at(i).id() == profileId)
+		{
+			m_currentProfile = i;
+			return true;
+		}
+	}
+	return false;
+}
+
+void MojangAccount::loadProfiles(const ProfileList& profiles)
+{
+	m_profiles.clear();
+	for (auto profile : profiles)
+		m_profiles.append(profile);
+}
+
+MojangAccountPtr MojangAccount::loadFromJson(const QJsonObject& object)
+{
+	// The JSON object must at least have a username for it to be valid.
+	if (!object.value("username").isString())
+	{
+		QLOG_ERROR() << "Can't load Mojang account info from JSON object. Username field is missing or of the wrong type.";
+		return nullptr;
+	}
+	
+	QString username = object.value("username").toString("");
+	QString clientToken = object.value("clientToken").toString("");
+	QString accessToken = object.value("accessToken").toString("");
+
+	QJsonArray profileArray = object.value("profiles").toArray();
+	if (profileArray.size() < 1)
+	{
+		QLOG_ERROR() << "Can't load Mojang account with username \"" << username << "\". No profiles found.";
+		return nullptr;
+	}
+
+	ProfileList profiles;
+	for (QJsonValue profileVal : profileArray)
+	{
+		QJsonObject profileObject = profileVal.toObject();
+		QString id = profileObject.value("id").toString("");
+		QString name = profileObject.value("name").toString("");
+		if (id.isEmpty() || name.isEmpty())
+		{
+			QLOG_WARN() << "Unable to load a profile because it was missing an ID or a name.";
+			continue;
+		}
+		profiles.append(AccountProfile(id, name));
+	}
+
+	MojangAccountPtr account(new MojangAccount(username, clientToken, accessToken));
+	account->loadProfiles(profiles);
+
+	// Get the currently selected profile.
+	QString currentProfile = object.value("activeProfile").toString("");
+	if (!currentProfile.isEmpty())
+		account->setProfile(currentProfile);
+
+	return account;
+}
+
+QJsonObject MojangAccount::saveToJson()
+{
+	QJsonObject json;
+	json.insert("username", username());
+	json.insert("clientToken", clientToken());
+	json.insert("accessToken", accessToken());
+
+	QJsonArray profileArray;
+	for (AccountProfile profile : m_profiles)
+	{
+		QJsonObject profileObj;
+		profileObj.insert("id", profile.id());
+		profileObj.insert("name", profile.name());
+		profileArray.append(profileObj);
+	}
+	json.insert("profiles", profileArray);
+
+	if (currentProfile() != nullptr)
+		json.insert("activeProfile", currentProfile()->id());
+
+	return json;
+}
+
+
+AccountProfile::AccountProfile(const QString& id, const QString& name)
+{
+	m_id = id;
+	m_name = name;
+}
+
+AccountProfile::AccountProfile(const AccountProfile& other)
+{
+	m_id = other.m_id;
+	m_name = other.m_name;
+}
+
+QString AccountProfile::id() const
+{
+	return m_id;
+}
+
+QString AccountProfile::name() const
+{
+	return m_name;
+}
+
+
diff --git a/logic/auth/MojangAccount.h b/logic/auth/MojangAccount.h
new file mode 100644
index 00000000..062b8aa2
--- /dev/null
+++ b/logic/auth/MojangAccount.h
@@ -0,0 +1,154 @@
+/* Copyright 2013 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <QObject>
+#include <QString>
+#include <QList>
+#include <QJsonObject>
+
+#include <memory>
+
+class MojangAccount;
+
+typedef std::shared_ptr<MojangAccount> MojangAccountPtr;
+Q_DECLARE_METATYPE(MojangAccountPtr)
+
+
+/**
+ * Class that represents a profile within someone's Mojang account.
+ *
+ * Currently, the profile system has not been implemented by Mojang yet,
+ * but we might as well add some things for it in MultiMC right now so
+ * we don't have to rip the code to pieces to add it later.
+ */
+class AccountProfile
+{
+public:
+	AccountProfile(const QString& id, const QString& name);
+	AccountProfile(const AccountProfile& other);
+
+	QString id() const;
+	QString name() const;
+protected:
+	QString m_id;
+	QString m_name;
+};
+
+
+typedef QList<AccountProfile> ProfileList;
+
+
+/**
+ * Object that stores information about a certain Mojang account.
+ *
+ * Said information may include things such as that account's username, client token, and access 
+ * token if the user chose to stay logged in.
+ */
+class MojangAccount : public QObject
+{
+Q_OBJECT
+public:
+	/**
+	 * Constructs a new MojangAccount with the given username.
+	 * The client token will be generated automatically and the access token will be blank.
+	 */
+	explicit MojangAccount(const QString& username, QObject* parent = 0);
+
+	/**
+	 * Constructs a new MojangAccount with the given username, client token, and access token.
+	 */
+	explicit MojangAccount(const QString& username, const QString& clientToken, const QString& accessToken, QObject* parent = 0);
+
+	/**
+	 * Constructs a new MojangAccount matching the given account.
+	 */
+	MojangAccount(const MojangAccount& other, QObject* parent);
+
+	/**
+	 * Loads a MojangAccount from the given JSON object.
+	 */
+	static MojangAccountPtr loadFromJson(const QJsonObject& json);
+
+	/**
+	 * Saves a MojangAccount to a JSON object and returns it.
+	 */
+	QJsonObject saveToJson();
+
+
+	/**
+	 * This MojangAccount's username. May be an email address if the account is migrated.
+	 */
+	QString username() const;
+
+	/**
+	 * This MojangAccount's client token. This is a UUID used by Mojang's auth servers to identify this client.
+	 * This is unique for each MojangAccount.
+	 */
+	QString clientToken() const;
+
+	/**
+	 * Sets the MojangAccount's client token to the given value.
+	 */
+	void setClientToken(const QString& token);
+
+	/**
+	 * This MojangAccount's access token.
+	 * If the user has not chosen to stay logged in, this will be an empty string.
+	 */
+	QString accessToken() const;
+
+	/**
+	 * Changes this MojangAccount's access token to the given value.
+	 */
+	void setAccessToken(const QString& token);
+
+	/**
+	 * Get full session ID
+	 */
+	QString sessionId() const;
+
+	/**
+	 * Returns a list of the available account profiles.
+	 */
+	const ProfileList profiles() const;
+
+	/**
+	 * Returns a pointer to the currently selected profile.
+	 * If no profile is selected, returns the first profile in the profile list or nullptr if there are none.
+	 */
+	const AccountProfile* currentProfile() const;
+
+	/**
+	 * Sets the currently selected profile to the profile with the given ID string.
+	 * If profileId is not in the list of available profiles, the function will simply return false.
+	 */
+	bool setProfile(const QString& profileId);
+
+	/**
+	 * Clears the current account profile list and replaces it with the given profile list.
+	 */
+	void loadProfiles(const ProfileList& profiles);
+
+
+protected:
+	QString m_username;
+	QString m_clientToken;
+	QString m_accessToken; // Blank if not logged in.
+	int m_currentProfile; // Index of the selected profile within the list of available profiles. -1 if nothing is selected.
+	ProfileList m_profiles; // List of available profiles.
+};
+
diff --git a/logic/auth/YggdrasilTask.cpp b/logic/auth/YggdrasilTask.cpp
new file mode 100644
index 00000000..39dfb749
--- /dev/null
+++ b/logic/auth/YggdrasilTask.cpp
@@ -0,0 +1,182 @@
+/* Copyright 2013 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <logic/auth/YggdrasilTask.h>
+
+#include <QObject>
+#include <QString>
+#include <QJsonObject>
+#include <QJsonDocument>
+#include <QNetworkReply>
+#include <QByteArray>
+
+#include <MultiMC.h>
+#include <logic/auth/MojangAccount.h>
+
+YggdrasilTask::YggdrasilTask(MojangAccountPtr account, QObject* parent) : Task(parent)
+{
+	m_error = nullptr;
+	m_account = account;
+}
+
+
+YggdrasilTask::~YggdrasilTask()
+{
+	if (m_error)
+		delete m_error;
+}
+
+void YggdrasilTask::executeTask()
+{
+	setStatus(getStateMessage(STATE_SENDING_REQUEST));
+
+	// Get the content of the request we're going to send to the server.
+	QJsonDocument doc(getRequestContent());
+
+	auto worker = MMC->qnam();
+	connect(worker.get(), SIGNAL(finished(QNetworkReply*)), this,
+			SLOT(processReply(QNetworkReply*)));
+
+	QUrl reqUrl("https://authserver.mojang.com/" + getEndpoint());
+	QNetworkRequest netRequest(reqUrl);
+	netRequest.setHeader(QNetworkRequest::ContentTypeHeader, "application/json");
+	
+	m_netReply = worker->post(netRequest, doc.toJson());
+}
+
+void YggdrasilTask::processReply(QNetworkReply* reply)
+{
+	setStatus(getStateMessage(STATE_PROCESSING_RESPONSE));
+
+	if (m_netReply != reply)
+		// Wrong reply for some reason...
+		return;
+
+	// Check for errors.
+	switch (reply->error())
+	{
+		case QNetworkReply::NoError:
+		{
+			// Try to parse the response regardless of the response code.
+			// Sometimes the auth server will give more information and an error code.
+			QJsonParseError jsonError;
+			QByteArray replyData = reply->readAll();
+			QJsonDocument doc = QJsonDocument::fromJson(replyData, &jsonError);
+
+			// Check the response code.
+			int responseCode = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();
+
+			switch (responseCode)
+			{
+				case 200:
+				{
+					// If the response code was 200, then there shouldn't be an error. Make sure anyways.
+					switch (jsonError.error)
+					{
+						case QJsonParseError::NoError:
+							if (!processResponse(doc.object()))
+							{
+								YggdrasilTask::Error* err = getError();
+								if (err)
+									emitFailed(err->getErrorMessage());
+								else
+									emitFailed(tr("An unknown error occurred when processing the response from the authentication server."));
+							}
+							else
+							{
+								emitSucceeded();
+							}
+						break;
+
+						default:
+						emitFailed(tr("Failed to parse Yggdrasil JSON response: \"%1\".").arg(jsonError.errorString()));
+						break;
+					}
+					break;
+				}
+
+				default:
+					// If the response code was something else, then Yggdrasil may have given us information about the error.
+					// If we can parse the response, then get information from it. Otherwise just say there was an unknown error.
+					switch (jsonError.error)
+					{
+						case QJsonParseError::NoError:
+							// We were able to parse the server's response. Woo!
+							// Call processError. If a subclass has overridden it then they'll handle their stuff there.
+							processError(doc.object());
+							break;
+
+						default:
+							// The server didn't say anything regarding the error. Give the user an unknown error.
+							emitFailed(tr("Login failed: Unknown HTTP code %1 encountered.").arg(responseCode));
+							break;
+					}
+					break;
+			}
+
+			break;
+		}
+
+		case QNetworkReply::OperationCanceledError:
+			emitFailed(tr("Login canceled."));
+			break;
+
+		default:
+			emitFailed(tr("An unknown error occurred when trying to communicate with the authentication server."));
+			break;
+	}
+}
+
+QString YggdrasilTask::processError(QJsonObject responseData)
+{
+	QJsonValue errorVal = responseData.value("error");
+	QJsonValue msgVal = responseData.value("errorMessage");
+	QJsonValue causeVal = responseData.value("cause");
+
+	if (errorVal.isString() && msgVal.isString() && causeVal.isString())
+	{
+		m_error = new Error(errorVal.toString(""), msgVal.toString(""), causeVal.toString(""));
+		return m_error->getDisplayMessage();
+	}
+	else
+	{
+		// Error is not in standard format. Don't set m_error and return unknown error.
+		return tr("An unknown Yggdrasil error occurred.");
+	}
+}
+
+QString YggdrasilTask::getStateMessage(const YggdrasilTask::State state) const
+{
+	switch (state)
+	{
+	case STATE_SENDING_REQUEST:
+		return tr("Sending request to auth servers.");
+	case STATE_PROCESSING_RESPONSE:
+		return tr("Processing response from servers.");
+	default:
+		return tr("Processing. Please wait.");
+	}
+}
+
+YggdrasilTask::Error *YggdrasilTask::getError() const
+{
+	return this->m_error;
+}
+
+MojangAccountPtr YggdrasilTask::getMojangAccount() const
+{
+	return this->m_account;
+}
+
diff --git a/logic/auth/YggdrasilTask.h b/logic/auth/YggdrasilTask.h
new file mode 100644
index 00000000..6aebae16
--- /dev/null
+++ b/logic/auth/YggdrasilTask.h
@@ -0,0 +1,128 @@
+/* Copyright 2013 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <logic/tasks/Task.h>
+
+#include <QString>
+#include <QJsonObject>
+
+#include "logic/auth/MojangAccount.h"
+
+class QNetworkReply;
+
+
+/**
+ * A Yggdrasil task is a task that performs an operation on a given mojang account.
+ */
+class YggdrasilTask : public Task
+{
+Q_OBJECT
+public:
+	explicit YggdrasilTask(MojangAccountPtr account, QObject* parent=0);
+	~YggdrasilTask();
+
+	/**
+	 * Class describing a Yggdrasil error response.
+	 */
+	class Error
+	{
+	public:
+		Error(const QString& shortError, const QString& errorMessage, const QString& cause) : 
+			m_shortError(shortError), m_errorMessage(errorMessage), m_cause(cause) {}
+
+		QString getShortError() const { return m_shortError; }
+		QString getErrorMessage() const { return m_errorMessage; }
+		QString getCause() const { return m_cause; }
+
+		/// Gets the string to display in the GUI for describing this error.
+		QString getDisplayMessage() { return getErrorMessage(); }
+
+	protected:
+		QString m_shortError;
+		QString m_errorMessage;
+		QString m_cause;
+	};
+
+	/**
+	 * Gets the Mojang account that this task is operating on.
+	 */
+	virtual MojangAccountPtr getMojangAccount() const;
+
+	/**
+	 * Returns a pointer to a YggdrasilTask::Error object if an error has occurred.
+	 * If no error has occurred, returns a null pointer.
+	 */
+	virtual Error* getError() const;
+
+protected:
+	/**
+	 * Enum for describing the state of the current task.
+	 * Used by the getStateMessage function to determine what the status message should be.
+	 */
+	enum State
+	{
+		STATE_SENDING_REQUEST,
+		STATE_PROCESSING_RESPONSE,
+		STATE_OTHER,
+	};
+
+	virtual void executeTask();
+
+	/**
+	 * Gets the JSON object that will be sent to the authentication server.
+	 * Should be overridden by subclasses.
+	 */
+	virtual QJsonObject getRequestContent() const = 0;
+
+	/**
+	 * Gets the endpoint to POST to.
+	 * No leading slash.
+	 */
+	virtual QString getEndpoint() const = 0;
+
+	/**
+	 * Processes the response received from the server.
+	 * If an error occurred, this should emit a failed signal and return false.
+	 * If Yggdrasil gave an error response, it should call setError() first, and then return false.
+	 * Otherwise, it should return true.
+	 */
+	virtual bool processResponse(QJsonObject responseData) = 0;
+
+	/**
+	 * Processes an error response received from the server.
+	 * The default implementation will read data from Yggdrasil's standard error response format and set it as this task's Error.
+	 * \returns a QString error message that will be passed to emitFailed.
+	 */
+	virtual QString processError(QJsonObject responseData);
+
+	/**
+	 * Returns the state message for the given state.
+	 * Used to set the status message for the task.
+	 * Should be overridden by subclasses that want to change messages for a given state.
+	 */
+	virtual QString getStateMessage(const State state) const;
+
+	MojangAccountPtr m_account;
+
+	QNetworkReply* m_netReply;
+
+	Error* m_error;
+
+protected slots:
+	void processReply(QNetworkReply* reply);
+};
+
diff --git a/logic/lists/MojangAccountList.cpp b/logic/lists/MojangAccountList.cpp
new file mode 100644
index 00000000..1d67c70f
--- /dev/null
+++ b/logic/lists/MojangAccountList.cpp
@@ -0,0 +1,349 @@
+/* Copyright 2013 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "logic/lists/MojangAccountList.h"
+
+#include <QIODevice>
+#include <QFile>
+#include <QTextStream>
+#include <QJsonDocument>
+#include <QJsonArray>
+#include <QJsonObject>
+#include <QJsonParseError>
+
+#include "logger/QsLog.h"
+
+#include "logic/auth/MojangAccount.h"
+
+#define ACCOUNT_LIST_FORMAT_VERSION 1
+
+MojangAccountList::MojangAccountList(QObject *parent) : QAbstractListModel(parent)
+{
+}
+
+MojangAccountPtr MojangAccountList::findAccount(const QString &username) const
+{
+	for (int i = 0; i < count(); i++)
+	{
+		MojangAccountPtr account = at(i);
+		if (account->username() == username)
+			return account;
+	}
+	return nullptr;
+}
+
+
+const MojangAccountPtr MojangAccountList::at(int i) const
+{
+	return MojangAccountPtr(m_accounts.at(i));
+}
+
+void MojangAccountList::addAccount(const MojangAccountPtr account)
+{
+	beginResetModel();
+	m_accounts.append(account);
+	endResetModel();
+	onListChanged();
+}
+
+void MojangAccountList::removeAccount(const QString& username)
+{
+	beginResetModel();
+	for (auto account : m_accounts)
+	{
+		if (account->username() == username)
+		{
+			m_accounts.removeOne(account);
+			return;
+		}
+	}
+	endResetModel();
+	onListChanged();
+}
+
+void MojangAccountList::removeAccount(QModelIndex index)
+{
+	beginResetModel();
+	m_accounts.removeAt(index.row());
+	endResetModel();
+	onListChanged();
+}
+
+
+MojangAccountPtr MojangAccountList::activeAccount() const
+{
+	if (m_activeAccount.isEmpty())
+		return nullptr;
+	else
+		return findAccount(m_activeAccount);
+}
+
+void MojangAccountList::setActiveAccount(const QString& username)
+{
+	beginResetModel();
+	for (MojangAccountPtr account : m_accounts)
+		if (account->username() == username)
+			m_activeAccount = username;
+	endResetModel();
+	onListChanged();
+}
+
+
+void MojangAccountList::onListChanged()
+{
+	if (m_autosave)
+		// TODO: Alert the user if this fails.
+		saveList();
+	emit listChanged();
+}
+
+
+int MojangAccountList::count() const
+{
+	return m_accounts.count();
+}
+
+
+QVariant MojangAccountList::data(const QModelIndex &index, int role) const
+{
+	if (!index.isValid())
+		return QVariant();
+
+	if (index.row() > count())
+		return QVariant();
+
+	MojangAccountPtr account = at(index.row());
+
+	switch (role)
+	{
+	case Qt::DisplayRole:
+		switch (index.column())
+		{
+		case ActiveColumn:
+			return account->username() == m_activeAccount;
+
+		case NameColumn:
+			return account->username();
+
+		default:
+			return QVariant();
+		}
+
+	case Qt::ToolTipRole:
+		return account->username();
+
+	case PointerRole:
+		return qVariantFromValue(account);
+
+	default:
+		return QVariant();
+	}
+}
+
+QVariant MojangAccountList::headerData(int section, Qt::Orientation orientation, int role) const
+{
+	switch (role)
+	{
+	case Qt::DisplayRole:
+		switch (section)
+		{
+		case ActiveColumn:
+			return "Active?";
+
+		case NameColumn:
+			return "Name";
+
+		default:
+			return QVariant();
+		}
+
+	case Qt::ToolTipRole:
+		switch (section)
+		{
+		case NameColumn:
+			return "The name of the version.";
+
+		default:
+			return QVariant();
+		}
+
+	default:
+		return QVariant();
+	}
+}
+
+int MojangAccountList::rowCount(const QModelIndex &parent) const
+{
+	// Return count
+	return count();
+}
+
+int MojangAccountList::columnCount(const QModelIndex &parent) const
+{
+	return 2;
+}
+
+void MojangAccountList::updateListData(QList<MojangAccountPtr> versions)
+{
+	beginResetModel();
+	m_accounts = versions;
+	endResetModel();
+}
+
+bool MojangAccountList::loadList(const QString& filePath)
+{
+	QString path = filePath;
+	if (path.isEmpty()) path = m_listFilePath;
+	if (path.isEmpty())
+	{
+		QLOG_ERROR() << "Can't load Mojang account list. No file path given and no default set.";
+		return false;
+	}
+
+	QFile file(path);
+	
+	// Try to open the file and fail if we can't.
+	// TODO: We should probably report this error to the user.
+	if (!file.open(QIODevice::ReadOnly))
+	{
+		QLOG_ERROR() << QString("Failed to read the account list file (%1).").arg(path).toUtf8();
+		return false;
+	}
+
+	// Read the file and close it.
+	QByteArray jsonData = file.readAll();
+	file.close();
+
+	QJsonParseError parseError;
+	QJsonDocument jsonDoc = QJsonDocument::fromJson(jsonData, &parseError);
+
+	// Fail if the JSON is invalid.
+	if (parseError.error != QJsonParseError::NoError)
+	{
+		QLOG_ERROR() << QString("Failed to parse account list file: %1 at offset %2")
+							.arg(parseError.errorString(), QString::number(parseError.offset))
+							.toUtf8();
+		return false;
+	}
+
+	// Make sure the root is an object.
+	if (!jsonDoc.isObject())
+	{
+		QLOG_ERROR() << "Invalid account list JSON: Root should be an array.";
+		return false;
+	}
+
+	QJsonObject root = jsonDoc.object();
+
+	// Make sure the format version matches.
+	if (root.value("formatVersion").toVariant().toInt() != ACCOUNT_LIST_FORMAT_VERSION)
+	{
+		QString newName = "accounts-old.json";
+		QLOG_WARN() << "Format version mismatch when loading account list. Existing one will be renamed to"
+					<< newName;
+
+		// Attempt to rename the old version.
+		file.rename(newName);
+		return false;
+	}
+
+	// Now, load the accounts array.
+	beginResetModel();
+	QJsonArray accounts = root.value("accounts").toArray();
+	for (QJsonValue accountVal : accounts)
+	{
+		QJsonObject accountObj = accountVal.toObject();
+		MojangAccountPtr account = MojangAccount::loadFromJson(accountObj);
+		if (account.get() != nullptr)
+		{
+			m_accounts.append(account);
+		}
+		else
+		{
+			QLOG_WARN() << "Failed to load an account.";
+		}
+	}
+	endResetModel();
+
+	// Load the active account.
+	m_activeAccount = root.value("activeAccount").toString("");
+	
+	return true;
+}
+
+bool MojangAccountList::saveList(const QString& filePath)
+{
+	QString path(filePath);
+	if (path.isEmpty()) path = m_listFilePath;
+	if (path.isEmpty())
+	{
+		QLOG_ERROR() << "Can't save Mojang account list. No file path given and no default set.";
+		return false;
+	}
+
+	QLOG_INFO() << "Writing account list to" << path;
+
+	QLOG_DEBUG() << "Building JSON data structure.";
+	// Build the JSON document to write to the list file.
+	QJsonObject root;
+
+	root.insert("formatVersion", ACCOUNT_LIST_FORMAT_VERSION);
+
+	// Build a list of accounts.
+	QLOG_DEBUG() << "Building account array.";
+	QJsonArray accounts;
+	for (MojangAccountPtr account : m_accounts)
+	{
+		QJsonObject accountObj = account->saveToJson();
+		accounts.append(accountObj);
+	}
+
+	// Insert the account list into the root object.
+	root.insert("accounts", accounts);
+
+	// Save the active account.
+	root.insert("activeAccount", m_activeAccount);
+
+	// Create a JSON document object to convert our JSON to bytes.
+	QJsonDocument doc(root);
+
+
+	// Now that we're done building the JSON object, we can write it to the file.
+	QLOG_DEBUG() << "Writing account list to file.";
+	QFile file(path);
+
+	// Try to open the file and fail if we can't.
+	// TODO: We should probably report this error to the user.
+	if (!file.open(QIODevice::WriteOnly))
+	{
+		QLOG_ERROR() << QString("Failed to read the account list file (%1).").arg(path).toUtf8();
+		return false;
+	}
+
+	// Write the JSON to the file.
+	file.write(doc.toJson());
+	file.close();
+
+	QLOG_INFO() << "Saved account list to" << path;
+
+	return true;
+}
+
+void MojangAccountList::setListFilePath(QString path, bool autosave)
+{
+	m_listFilePath = path;
+	autosave = autosave;
+}
+
diff --git a/logic/lists/MojangAccountList.h b/logic/lists/MojangAccountList.h
new file mode 100644
index 00000000..71f472f7
--- /dev/null
+++ b/logic/lists/MojangAccountList.h
@@ -0,0 +1,175 @@
+/* Copyright 2013 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <QObject>
+#include <QVariant>
+#include <QAbstractListModel>
+#include <QSharedPointer>
+
+#include "logic/auth/MojangAccount.h"
+
+
+/*!
+ * \brief List of available Mojang accounts.
+ * This should be loaded in the background by MultiMC on startup.
+ *
+ * This class also inherits from QAbstractListModel. Methods from that
+ * class determine how this list shows up in a list view. Said methods
+ * all have a default implementation, but they can be overridden by subclasses to
+ * change the behavior of the list.
+ */
+class MojangAccountList : public QAbstractListModel
+{
+	Q_OBJECT
+public:
+	enum ModelRoles
+	{
+		PointerRole = 0x34B1CB48
+	};
+
+	enum VListColumns
+	{
+		// TODO: Add icon column.
+		
+		// First column - Active?
+		ActiveColumn = 0,
+		
+		// Second column - Name
+		NameColumn,
+	};
+
+	explicit MojangAccountList(QObject *parent = 0);
+
+	//! Gets the account at the given index.
+	virtual const MojangAccountPtr at(int i) const;
+
+	//! Returns the number of accounts in the list.
+	virtual int count() const;
+
+	//////// List Model Functions ////////
+	virtual QVariant data(const QModelIndex &index, int role) const;
+	virtual QVariant headerData(int section, Qt::Orientation orientation, int role) const;
+	virtual int rowCount(const QModelIndex &parent) const;
+	virtual int columnCount(const QModelIndex &parent) const;
+
+	/*!
+	 * Adds a the given Mojang account to the account list.
+	 */
+	virtual void addAccount(const MojangAccountPtr account);
+
+	/*!
+	 * Removes the mojang account with the given username from the account list.
+	 */
+	virtual void removeAccount(const QString& username);
+
+	/*!
+	 * Removes the account at the given QModelIndex.
+	 */
+	virtual void removeAccount(QModelIndex index);
+
+	/*!
+	 * \brief Finds an account by its username.
+	 * \param The username of the account to find.
+	 * \return A const pointer to the account with the given username. NULL if
+	 * one doesn't exist.
+	 */
+	virtual MojangAccountPtr findAccount(const QString &username) const;
+	
+	/*!
+	 * Sets the default path to save the list file to.
+	 * If autosave is true, this list will automatically save to the given path whenever it changes.
+	 * THIS FUNCTION DOES NOT LOAD THE LIST. If you set autosave, be sure to call loadList() immediately
+	 * after calling this function to ensure an autosaved change doesn't overwrite the list you intended
+	 * to load.
+	 */
+	virtual void setListFilePath(QString path, bool autosave=false);
+
+	/*!
+	 * \brief Loads the account list from the given file path.
+	 * If the given file is an empty string (default), will load from the default account list file.
+	 * \return True if successful, otherwise false.
+	 */
+	virtual bool loadList(const QString& file="");
+
+	/*!
+	 * \brief Saves the account list to the given file.
+	 * If the given file is an empty string (default), will save from the default account list file.
+	 * \return True if successful, otherwise false.
+	 */
+	virtual bool saveList(const QString& file="");
+
+	/*!
+	 * \brief Gets a pointer to the account that the user has selected as their "active" account.
+	 * Which account is active can be overridden on a per-instance basis, but this will return the one that
+	 * is set as active globally.
+	 * \return The currently active MojangAccount. If there isn't an active account, returns a null pointer.
+	 */
+	virtual MojangAccountPtr activeAccount() const;
+
+	/*!
+	 * Sets the given account as the current active account.
+	 */
+	virtual void setActiveAccount(const QString& username);
+
+signals:
+	/*!
+	 * Signal emitted to indicate that the account list has changed.
+	 * This will also fire if the value of an element in the list changes (will be implemented later).
+	 */
+	void listChanged();
+
+protected:
+	/*!
+	 * Called whenever the list changes.
+	 * This emits the listChanged() signal and autosaves the list (if autosave is enabled).
+	 */
+	void onListChanged();
+
+	QList<MojangAccountPtr> m_accounts;
+
+	/*!
+	 * Username of the account that is currently active.
+	 * Empty string if no account is active.
+	 */
+	QString m_activeAccount;
+
+	//! Path to the account list file. Empty string if there isn't one.
+	QString m_listFilePath;
+
+	/*!
+	 * If true, the account list will automatically save to the account list path when it changes.
+	 * Ignored if m_listFilePath is blank.
+	 */
+	bool m_autosave;
+
+protected
+slots:
+	/*!
+	 * Updates this list with the given list of accounts.
+	 * This is done by copying each account in the given list and inserting it
+	 * into this one.
+	 * We need to do this so that we can set the parents of the accounts are set to this
+	 * account list. This can't be done in the load task, because the accounts the load
+	 * task creates are on the load task's thread and Qt won't allow their parents
+	 * to be set to something created on another thread.
+	 * To get around that problem, we invoke this method on the GUI thread, which
+	 * then copies the accounts and sets their parents correctly.
+	 * \param accounts List of accounts whose parents should be set.
+	 */
+	virtual void updateListData(QList<MojangAccountPtr> versions);
+};
+